Pondweed Family

Mostly freshwater perennial herbs rooted in the substrate with creeping, budding rhizomes. Leaves spirally arranged, blades linear or expanded when floating, with parallel venation and a basal sheath and ligule. Flower clusters in spikes held above the water. Flowers regular, bisexual, 4-parted, small. Perianth segments fleshy. Stamens 4, opposite and joined to the perianth segments. Ovary superior. Carpels 4, alternating with the stamens. Fruit a head of nutlets or drupelets, usually floating.

Grown in ponds and sometimes in aquaria.

2 genera and about 90-100 species, cosmopolitan. Australia has 2 genera and about 10 species.

Leaves floating and submerged; flowers bisexual, 4-parted; ovules 1 per carpel.

Source: Spencer, R. (2005). Potamogetonaceae. In: Spencer, R.. Horticultural Flora of South-eastern Australia. Volume 5. Flowering plants. Monocotyledons. The identification of garden and cultivated plants. University of New South Wales Press.

kingdom Plantae
phylum   Tracheophyta
class    Magnoliopsida
superorder     Lilianae
order      Alismatales
Higher taxa
Subordinate taxa
genus        Potamogeton L.